Which of the following statements is correct regarding chromium in water?

Correct option is A

Chromium in water primarily exists in two oxidation states: Chromium (III) and Chromium (VI).
Chromium (III):
· Found in insoluble forms due to its strong tendency to form precipitates or associate with organic matter.
· Less soluble compared to Chromium (VI).
Chromium (VI):
· Highly soluble and mobile in water.
· It is also more toxic and carcinogenic compared to Chromium (III).
Information Booster: · Chromium Sources: Found in industrial waste (electroplating, leather tanning) and natural weathering.
· Environmental Impact of Chromium:
· Chromium (VI) is a major pollutant due to its toxicity.
· Chromium (III) is less toxic and often used as a dietary supplement.
· Reduction Pathways: Chromium (VI) can be reduced to Chromium (III) using reducing agents (e.g., ferrous sulfate), which decreases its toxicity.
· Health Impact:
· Chromium (VI): Carcinogenic and affects respiratory and gastrointestinal systems.
· Chromium (III): Necessary in trace amounts but toxic in higher doses.
Additional Knowledge: 1. Chromium (III):
· Stable in reducing environments.
· Precipitates easily as chromium hydroxides.
2. Chromium (VI):
· Stable in oxidizing environments.
· Commonly present in the form of chromate (CrO₄²⁻) or dichromate (Cr₂O₇²⁻).
3. Regulation Limits:
· Drinking water standards typically limit Chromium (VI) to 0.05 mg/L due to its toxicity.
4. Applications of Chromium:
· Chromium (III): Tanning leather.
· Chromium (VI): Used in pigments, metal plating, and stainless steel production.